algebra

posted by .

could you please show me how to do this problem?
ballfield costs 14,850,00 to build. the cost per city resident to build it will be based on last census. New census shows population increased by 2200 people, which reduced the cost per resident $75. what is the current population of the city?? thank you

  • algebra -

    The way you grouped the cost by thousands, I think you left out a zero
    is it 14 850 000 ?

    let currect population be x
    last year's population is x - 2200

    currect cost per person = 14850000/x
    last year's cost per person = 14850000/(x-2200)

    14850000/(x-2200) - 14850000/x = 75
    14850000x - 14850000(x-2) = 75x(x-2200)

    75x^2 - 165000x - 14850000(2200) = 0
    x^2 - 2200x = 435 600 000
    x^2 - 2200x + 1210000 = 435 600 000 + 1 210 000
    (x - 1100)^2 = 436 810 000
    x - 1100 = 20900
    x = 22 000

    check:
    current pop: = 22000
    cost per person = 14850000/22000 = 675

    last years' pop = 19800
    cost per person = 14850000/19800 = 750

    change = 750-675 = 75 , YEAHH!

  • algebra -

    yes you were right about the zero. Thank you so much for showing me how to do it. ann

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. Algebra 1- 8th Grade

    According to the 1990 Census, the population of the United States was 2.49 x 10^8. The cost of taking the census in 1990 was 2.6 x 10^9 dollars. How much did the census cost per person in the United States?
  2. Math Help

    8. One nanometer is about 0.00000003937 of an inch. What is this number in standard notation?
  3. Math (algebra)

    I have no idea how to solve this problem... A village wants to build a community center that is projected to cost 1.2 million dollars. Cost per resident is increased by #$ as it is discovered that there are 225 fewer residents than …
  4. Algebra 2

    According to the US Census Bureau, the population of the United States has been growing at an average rate of approximately 2% per year. The census is taken every 10 years, and the population in 1980 was estimated at 226 million people. …
  5. math

    The2010 census shows that the population of New Jersey increased by 4.5%. If the 2010 population was 8,791,894, what was the population in 2000?
  6. History

    With over eight million people, New York City is the most heavily populated city in the U.S. Between 1800 and 1900, the population of New York increased from about 80,000 to over three million people. In the years after the Civil War, …
  7. Algebra 1

    Algebra 1 word problems help please 1. Madison is making a vinaigrette for her catering service using olive oil that costs 50 cents per ounce and apple cider vinegar that costs 35 cents an ounce.The ideal batch of vinaigrette has 25% …
  8. history

    With over eight million people, New York City is the most heavily populated city in the U.S. Between 1800 and 1900, the population of New York increased from about 80,000 to over three million people. In the years after the Civil War, …
  9. History

    19.)With over eight million people, New York City is most heavily populated city in the U.S Between 1800 & 1900, the population of New York increased from about 80,000 to over three million people. In the years after the Civil War, …
  10. History

    13.)With over eight million people, New York City is the most heavily populated city in the U.S. Between 1800 and 1900, the population of New York increased from about 80,000 to over three million people. In the years after the Civil …

More Similar Questions